`, favicon, and body of `Root()` to\nmatch your app's existing `index.html`, and stamp anything else your shell\nreferences directly (images, css) with `immutableFileUrl()`.\n\n1. Create `frontend/root.tsx`:\n\n```tsx\n/** @jsxImportSource npm:hono@4/jsx */\nimport { raw } from \"npm:hono@4/html\";\nimport { immutableFileUrl } from \"https://esm.town/v/std/utils/index.ts\";\n\n// The HTML shell for the app. It is never cached, so immutableFileUrl can stamp\n// the current val version into each asset URL — the browser caches those\n// immutably, and publishing the val changes the URLs, refetching exactly once.\nexport function Root() {\n return (\n <>\n {raw(\"<!DOCTYPE html>\")}\n <html lang=\"en\">\n <head>\n <meta charSet=\"UTF-8\" />\n <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" />\n <title>React Hono Val Town Starter

[{"_1":2,"_3":-5,"_4":-5},"loaderData",{"_5":6,"_7":8,"_9":10},"actionData","errors","root",{"_368":369,"_370":371},"routes/_app.x.$handle.$name",{"_11":12,"_13":14,"_15":16,"_18":19,"_17":-7,"_277":-5,"_20":278,"_22":279,"_280":281,"_282":283,"_26":284,"_24":285,"_286":-5,"_287":-5,"_288":54,"_289":290,"_291":45,"_292":-5,"_293":-5,"_294":295},"routes/_app.x.$handle.$name.branch.$branch.code.$",{"_11":12,"_13":14,"_15":16,"_17":-7,"_18":19,"_20":21,"_22":23,"_24":25,"_26":27,"_28":-5,"_29":-5,"_30":-5,"_31":-5,"_32":-5},"handle","test_account_001","name","discovery-radar","branchName","main","version","path","lib/lastfm.ts","project",{"_33":220,"_13":14,"_46":221,"_222":-5,"_223":54,"_224":225,"_226":225,"_227":228,"_229":-5,"_230":231,"_232":66,"_233":45,"_234":-5,"_235":-5,"_236":48,"_237":238,"_239":240,"_241":242,"_243":244,"_245":-5,"_246":247,"_248":247,"_249":250,"_251":250,"_252":250,"_253":247,"_254":247,"_255":256,"_257":258,"_259":260,"_261":54},"tree",[58,59,60,61,62,63],"file",{"_33":34,"_13":35,"_36":37,"_38":39,"_40":41,"_42":43,"_44":45,"_46":47,"_17":48,"_49":50,"_51":52,"_53":54,"_55":-5,"_18":56},"contents",[],"upstream","pull","ahead","behind","envVars","id","e0a7bbb2-6d4c-4303-a202-f41c8d529a3e","lastfm.ts","fileId","dad3dac8-9e53-11f1-9263-1607ee4eb77e","parentId","c7683d5c-9a27-4579-941f-911577aa8cb5","branchId","dc1f9fe4-aa8c-400d-87f3-9d22e6847153","branchVersion",85,"latest",true,"createdAt",["D",1787421841591],0,"fileType","script","content","/**\n * Last.fm API client (read-only, needs just an API key, no OAuth).\n * Used for discovery: similar-artist graph, genre/mood tags, listener counts\n * (obscurity signal), and top tracks. Spotify search maps Last.fm tracks to\n * real Spotify track URIs so they can be written to a Spotify playlist.\n */\nconst API_KEY = Deno.env.get(\"LASTFM_API_KEY\") ?? \"\";\nconst BASE = \"https://ws.audioscrobbler.com/2.0/\";\n\ninterface LfResult {\n error?: number;\n message?: string;\n [k: string]: unknown;\n}\n\nasync function lf(params: Record): Promise {\n const p = new URLSearchParams({ api_key: API_KEY, format: \"json\", ...params });\n const res = await fetch(`${BASE}?${p.toString()}`);\n if (!res.ok) throw new Error(`Last.fm HTTP ${res.status}`);\n const j = (await res.json()) as LfResult;\n if (j.error) throw new Error(`Last.fm ${j.error}: ${j.message ?? \"error\"}`);\n return j;\n}\n\nexport interface LfImage {\n size: string;\n url: string;\n}\n\n/** `artist.getSimilar` — the Last.fm similar-artist graph with a real match score. */\nexport async function getSimilar(\n artist: string,\n limit = 30,\n): Promise<{ similar: { name: string; match: number; image: LfImage[] }[]; tags: string[] }> {\n const j = await lf({ method: \"artist.getSimilar\", artist, limit: String(limit), autocorrect: \"1\" });\n const list = j.similarartists?.similarartist ?? [];\n const similar = (list as { name?: string; match?: string; image?: LfImage[] }[])\n .map((s) => ({\n name: s.name ?? \"\",\n match: parseFloat(s.match ?? \"0\") || 0,\n image: s.image ?? [],\n }))\n .filter((s) => s.name);\n const tags = (j.similarartists?.tags?.tag ?? []).map((t: { name?: string }) => t.name ?? \"\");\n return { similar, tags };\n}\n\n/** `artist.getTopTags` — the genre/mood tags that act as our \"genres\". */\nexport async function getTopTags(artist: string): Promise {\n const j = await lf({ method: \"artist.getTopTags\", artist, autocorrect: \"1\" });\n return (j.toptags?.tag ?? []).map((t: { name?: string }) => t.name ?? \"\").slice(0, 8);\n}\n\n/** `artist.getInfo` — listener count (obscurity signal) + image + url. */\nexport async function getInfo(\n artist: string,\n): Promise<{ listeners: number; playcount: number; url: string; image: LfImage[] }> {\n const j = await lf({ method: \"artist.getInfo\", artist, autocorrect: \"1\", lang: \"en\" });\n const stats = j.artist?.stats ?? {};\n return {\n listeners: parseInt(stats.listeners ?? \"0\", 10) || 0,\n playcount: parseInt(stats.playcount ?? \"0\", 10) || 0,\n url: j.artist?.url ?? \"\",\n image: j.artist?.image ?? [],\n };\n}\n\n/** `artist.getTopTracks` — an artist's most-played tracks. */\nexport async function getTopTracks(artist: string, limit = 5): Promise<{ name: string; playcount: number }[]> {\n const j = await lf({ method: \"artist.getTopTracks\", artist, limit: String(limit), autocorrect: \"1\" });\n return (j.toptracks?.track ?? [])\n .map((t: { name?: string; playcount?: string }) => ({\n name: t.name ?? \"\",\n playcount: parseInt(t.playcount ?? \"0\", 10) || 0,\n }))\n .filter((t: { name: string }) => t.name);\n}\n\n/** Best-looking image url from a Last.fm image array (extralarge > large > medium). */\nexport function bestImage(images: LfImage[]): string | undefined {\n for (const s of [\"extralarge\", \"large\", \"medium\"]) {\n const hit = images.find((i) => i.size === s && i.url);\n if (hit) return hit.url;\n }\n return undefined;\n}\n","deleted",false,"label",[57,35],"lib",{"_33":203,"_13":204,"_36":205,"_38":-5,"_40":41,"_42":206,"_44":45,"_46":207,"_17":48,"_49":95,"_51":-5,"_53":54,"_55":-5,"_72":208,"_18":209},{"_33":130,"_13":131,"_36":132,"_38":-5,"_40":41,"_42":87,"_44":45,"_46":133,"_17":48,"_49":95,"_51":-5,"_53":54,"_55":-5,"_72":134,"_18":135},{"_33":92,"_13":57,"_36":39,"_38":-5,"_40":41,"_42":93,"_44":45,"_46":94,"_17":48,"_49":95,"_51":-5,"_53":54,"_55":-5,"_72":96,"_18":97},{"_33":84,"_13":85,"_36":86,"_38":-5,"_40":41,"_42":87,"_44":45,"_46":88,"_17":48,"_49":24,"_51":89,"_53":54,"_55":-5,"_72":90,"_18":91},{"_33":75,"_13":76,"_36":77,"_38":-5,"_40":41,"_42":78,"_44":45,"_46":79,"_17":80,"_49":24,"_51":81,"_53":54,"_55":-5,"_72":82,"_18":83},{"_33":64,"_13":65,"_36":66,"_38":-5,"_40":41,"_42":67,"_44":45,"_46":68,"_17":69,"_49":70,"_51":71,"_53":54,"_55":14,"_72":73,"_18":74},"106246c6-5eb1-49a8-896e-0671d8647c82","index.ts","01a02a62-92f6-771d-907a-be2483e744c9",70,["D",1787421190662],10,"http","import { serveImmutableFile } from \"https://esm.town/v/std/utils/index.ts\";\nimport { Context, Hono } from \"npm:hono\";\nimport { getCookie, setCookie } from \"npm:hono/cookie\";\nimport { Root } from \"./frontend/root.tsx\";\nimport { StoredUser, getUser, init, upsertUser } from \"./lib/db.ts\";\nimport { authorizeUrl, exchangeCode } from \"./lib/spotify.ts\";\nimport { computeProfile, discover, updateDiscoveryPlaylist } from \"./lib/taste.ts\";\n\nawait init();\n\nconst app = new Hono();\nconst COOKIE = \"discovery_radar_user\";\n\nasync function getSessionUser(c: Context): Promise {\n const id = getCookie(c, COOKIE);\n return id ? getUser(id) : null;\n}\n\n// Serve the (never-cached) HTML shell at the root\napp.get(\"/\", (c) => c.html(Root()));\n\n// Serve frontend files, cached immutably\napp.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path));\n\n// ---- Spotify OAuth ----\napp.get(\"/auth/login\", (c) => {\n const state = crypto.randomUUID();\n setCookie(c, \"discovery_radar_state\", state, { path: \"/\", httpOnly: true, sameSite: \"Lax\" });\n return c.redirect(authorizeUrl(state));\n});\n\napp.get(\"/auth/callback\", async (c) => {\n const code = c.req.query(\"code\");\n if (!code) return c.text(\"Missing authorization code\", 400);\n try {\n const tokens = await exchangeCode(code);\n const me = await (await fetch(\"https://api.spotify.com/v1/me\", {\n headers: { authorization: `Bearer ${tokens.access_token}` },\n })).json();\n await upsertUser({\n spotifyId: me.id,\n displayName: me.display_name ?? \"Spotify user\",\n accessToken: tokens.access_token,\n refreshToken: tokens.refresh_token ?? \"\",\n expiresAt: Date.now() + tokens.expires_in * 1000,\n });\n setCookie(c, COOKIE, me.id, {\n path: \"/\",\n httpOnly: true,\n sameSite: \"Lax\",\n maxAge: 60 * 60 * 24 * 30,\n });\n return c.redirect(\"/\");\n } catch (e) {\n console.error(\"callback failed\", e);\n return c.text(\"Spotify auth failed: \" + (e as Error).message, 500);\n }\n});\n\napp.post(\"/auth/logout\", (c) => {\n setCookie(c, COOKIE, \"\", { path: \"/\", httpOnly: true, sameSite: \"Lax\", maxAge: 0 });\n return c.redirect(\"/\");\n});\n\n// ---- API ----\napp.get(\"/api/me\", async (c) => {\n const u = await getSessionUser(c);\n return c.json(u ? { connected: true, displayName: u.displayName } : { connected: false });\n});\n\napp.get(\"/api/profile\", async (c) => {\n const u = await getSessionUser(c);\n if (!u) return c.json({ error: \"unauthorized\" }, 401);\n return c.json({ profile: await computeProfile(u) });\n});\n\napp.get(\"/api/discover\", async (c) => {\n const u = await getSessionUser(c);\n if (!u) return c.json({ error: \"unauthorized\" }, 401);\n const profile = await computeProfile(u);\n const obscurity = parseFloat(c.req.query(\"obscurity\") ?? \"\");\n const genre = c.req.query(\"genre\");\n const seed = parseFloat(c.req.query(\"seed\") ?? \"\");\n const picks = await discover(u, profile, {\n obscurity: Number.isFinite(obscurity) ? obscurity : undefined,\n genres: genre ? [genre] : undefined,\n seed: Number.isFinite(seed) ? seed : undefined,\n });\n return c.json({ profile, genres: profile.map((a) => a.label), picks });\n});\n\napp.post(\"/api/save\", async (c) => {\n const u = await getSessionUser(c);\n if (!u) return c.json({ error: \"unauthorized\" }, 401);\n try {\n const body = await c.req.json<{ trackUris: string[] }>();\n const playlistId = await updateDiscoveryPlaylist(u, body.trackUris ?? []);\n return c.json({ ok: true, playlistId });\n } catch (e) {\n const msg = (e as Error).message || \"save failed\";\n console.error(\"save failed:\", e);\n return c.json(\n { ok: false, error: \"Spotify blocked playlist access: \" + msg },\n 502,\n );\n }\n});\n\n// Unwrap and rethrow Hono errors as the original error\napp.onError((err) => Promise.reject(err));\n\nexport default app.fetch;\n","children",[],[65],"3b240b35-7549-4e28-98dc-b0dbd93fdb6d","README.md","01a02a62-92f6-771d-907a-b81da57860c2",90,["D",1787421893911],7,"# 🎧 Discovery Radar\n\nA personal Spotify discovery app that breaks you out of the same 50 artists.\n\nDiscovery runs on the **Last.fm API** (open, read-only with an API key). It computes\n**your sound profile** from Last.fm genre/mood tags, then crawls the **similar-artist\ngraph** for under-discovered acts (ranked by tag-match and listener-count obscurity).\nBecause you listen on Spotify, the app maps each Last.fm track to a **real Spotify\ntrack URI** (via search) and writes your picks to a **Spotify playlist** — and the\nweekly cron keeps it fresh.\n\n## How it works\n\n```mermaid\ngraph LR\n Browser -->|\"Connect Spotify\"| Hono[\"index.ts
(Hono + OAuth)\"]\n Hono -->|stores tokens| DB[(SQLite)]\n Hono -->|computeProfile + discover| SP[\"Spotify API\"]\n SP -->|top artists + genre search| Hono\n Hono -->|radar data + picks| React[\"React app
(radar charts)\"]\n Cron[\"cron/refresh.ts
(weekly)\"] -->|refresh playlist| SP\n```\n\n- `index.ts` — Hono server: Spotify OAuth, session cookie, `/api/me`,\n `/api/profile`, `/api/discover`, `/api/save`.\n- `lib/spotify.ts` — OAuth + Spotify API client. Used for your top artists\n (discovery seeds), mapping tracks to Spotify URIs, and writing playlists.\n- `lib/lastfm.ts` — Last.fm client: similar artists, tags, listener counts, top tracks.\n- `lib/taste.ts` — taste profile (Last.fm tags), discovery, Spotify playlist writer.\n- `lib/db.ts` — SQLite storage for per-user Spotify tokens + playlist id.\n- `frontend/` — React app with a constellation map + grid views.\n- `cron/refresh.ts` — weekly job that refreshes each user's \"Discovery Radar\"\n playlist (Sundays 12:00 UTC).\n\n## Setup\n\n1. Create a **Last.fm API account** at \n and copy your API key.\n2. Set the Last.fm key below.\n\n👉 Add LASTFM_API_KEY here: https://www.val.town/x/test_account_001/discovery-radar/environment-variables?key=LASTFM_API_KEY\n\n3. Spotify (needed only for your listening): create a Spotify app at\n , add the redirect URI\n `https://discovery-radar.val.run/auth/callback`, and set the two env vars below.\n\n👉 Add SPOTIFY_CLIENT_ID here: https://www.val.town/x/test_account_001/discovery-radar/environment-variables?key=SPOTIFY_CLIENT_ID\n\n👉 Add SPOTIFY_CLIENT_SECRET here: https://www.val.town/x/test_account_001/discovery-radar/environment-variables?key=SPOTIFY_CLIENT_SECRET\n\n`SPOTIFY_REDIRECT_URI` is optional — it defaults to the callback URL above.\n\n4. Open the app, hit **Connect Spotify**, authorize, and your taste profile and\n a galaxy of discovered artists appear. Hit **Save** to write them to a\n private \"Discovery Radar\" Spotify playlist.\n\n## Notes\n\n- **Discovery = Last.fm; playlists = Spotify.** This app's Spotify grant is\n restricted (no audio-features / recommendations / browse), so discovery moved\n entirely to Last.fm's open API. Spotify read is only used for your top\n artists and for mapping tracks to URIs — and Spotify *write* (playlists)\n works fine.\n- Obscurity is driven by Last.fm **listener counts** (logged to a 0–100\n \"Popularity\").\n- The match % is tag overlap with your taste profile; the radar is your tag\n profile vs each artist's tags.\n- The weekly cron refreshes the playlist for every connected user.\n- If \"Save\" errors with \"Spotify blocked playlist access\", the token is missing\n `playlist-modify-*` scopes — disconnect and reconnect Spotify to re-consent.\n",[],[76],"4fe8db74-919d-4686-9be5-883aad74c74f","CHANGELOG.md","01a02a62-92f6-771d-907a-b61ebd4f10fe",1,["D",1787417498284],"# Changelog\n\n## 2026-07-30 — Immutable asset caching\n\nFrontend files are now served at version-addressed URLs\n(`/__immutable/45/frontend/index.tsx`) with\n`Cache-Control: public, max-age=31536000, immutable`, so repeat visits load the\nwhole client graph from the browser cache — roughly 3× faster (~665ms → ~157ms\nmeasured). Publishing your val bumps its version, which changes every URL, so\ncaches invalidate automatically. Old-version URLs return 404 after a publish\n(like Next.js build assets); a reload picks up the new version.\n\nWhat changed in the template:\n\n- `frontend/index.html` → [`frontend/root.tsx`](/frontend/root.tsx): the HTML\n shell is now JSX and stamps asset URLs with `immutableFileUrl()`\n- [`index.ts`](/index.ts): serves `Root()` at `/`, and one\n `app.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path))` route\n serves all frontend files\n\n### Upgrading an existing remix\n\nYour copy of this template doesn't update automatically. Two options:\n\n**Minimal (most of the benefit):** point both routes at `serveImmutableFile` —\nyour existing bare URLs redirect into versioned space, the new route serves\nthem, and the whole module graph gets cached (costs one redirect per page view):\n\n```ts\nimport { serveImmutableFile } from \"https://esm.town/v/std/utils/index.ts\";\n\napp.get(\"/__immutable/*\", (c) => serveImmutableFile(c.req.path));\napp.get(\"/frontend/**/*\", (c) => serveImmutableFile(c.req.path)); // was serveFile\n```\n\n**Full upgrade (also removes the redirect):** three self-contained steps —\nno other files needed. Adjust the ``, favicon, and body of `Root()` to\nmatch your app's existing `index.html`, and stamp anything else your shell\nreferences directly (images, css) with `immutableFileUrl()`.\n\n1. Create `frontend/root.tsx`:\n\n```tsx\n/** @jsxImportSource npm:hono@4/jsx */\nimport { raw } from \"npm:hono@4/html\";\nimport { immutableFileUrl } from \"https://esm.town/v/std/utils/index.ts\";\n\n// The HTML shell for the app. It is never cached, so immutableFileUrl can stamp\n// the current val version into each asset URL — the browser caches those\n// immutably, and publishing the val changes the URLs, refetching exactly once.\nexport function Root() {\n return (\n <>\n {raw(\"<!DOCTYPE html>\")}\n <html lang=\"en\">\n <head>\n <meta charSet=\"UTF-8\" />\n <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" />\n <title>React Hono Val Town Starter\n